Projectile launchers are well known, and can be mounted on a rifle (typically beneath), or operated independently. In either case, it is known to have a barrel which pivots to one side about a generally vertical axis, from a forward pivot point, to expose the breech end of the barrel for manual loading of the projectile. For a person who shoots right-handed, it is typical for the breech end to swing open to the left, for loading of a projectile with the left hand. For a person who shoots left-handed, of course it is preferable for the breech to swing open to the right.
An obvious difficulty with this arrangement is that a launcher configured for use by a right-handed shot is not well-configured for use by someone who is a left-handed shot. Thus it is known to manufacture two versions of any particular launcher, namely a right-handed version and a left-handed version. For obvious reasons, this is an undesirable situation. For one thing, it forces police or military units to stock a larger inventory of launchers than might otherwise be the case. Furthermore, in the field it does not provide a desirable degree of flexibility in terms of who can effectively use any given launcher.
Accordingly, a launcher which could readily be used by either a right or left handed user would offer significant advantages.